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In order to simulate the crack connection between cords and the inter-ply crack growth in the belt-layer of a real TBR (Truck and Bus Radial) tire, we tested two-ply rubber-cord laminate specimens with exposed edges in constant displacement control. We evaluated measurement of the crack connection when crack reaches the half of the length between 45° aligned cords, and measured the amount of the crack growth by the steel probe method. We then performed a two-dimensional analysis of the crack connection between cords at the exposed edges. The theoretical life of the specimens from the crack connection life between cords (the critical value) and from this critical value to the final failure can thus be calculated by the used of tearing energy. The theoretical life was compared with those of the experimental life. The life prediction up to the critical value has an error of 20% compared to experimental life, and up to the final failure about 65% error.

This paper presents the CAE technique to estimate the dynamic stress in a vehicle structure at an early stage in the vehicle design process, using modal stress superposition. Dynamic joint reaction forces are obtained by flexible multibody dynamics simulation using DADS. Stress influence coefficients are computed through the inertia relief analysis using MSC/NASTRAN. A test vehicle was run over a zigzag bump course with a constant speed of 40km/hr, and the results of the numerical analysis were compared to those of the test.

At the initial design stage of a new vehicle, chassis layout has the most important influence on overall vehicle performance. Most chassis designers have achieved target performances by trial and error as well as by individual know-how. Accordingly, a general procedure for automatically determining the optimum location of suspension hard points with respect to the kinematic characteristics needs to be created. In this paper, a method to optimize the toe angle in the double wishbone-type front suspension of a four-wheel-drive vehicle is presented using design of experiments, multibody dynamic simulation, and an optimum design program. The handling performances of two full vehicle models having the initial and the optimized toe angle are compared using a simulation of a single lane change maneuver. Front and rear suspensions are modeled as rigid bodies connected by kinematic joints using DADS.

For the three-cylinder engine whose crankshaft has a phase of 120 degrees, the total sum of unbalanced inertia forces occurring in each cylinder will be counterbalanced among the three cylinders. However, parts of inertia forces generated at the No.1 and No.3 cylinders will cause a primary moment about the No.2 cylinder. In order to eliminate this out-of-balance moment, a single balance shaft has been attached to the cylinder block so that engine durability and ride comfort may be further improved. Accordingly, the forced vibration analysis of the three-cylinder engine must be implemented to meet the required targets at an early design stage. In this paper, a method to reduce noise and vibration in the 800cc, three-cylinder LPG engine is suggested using the multibody dynamics simulation. The static and dynamic balances of the three-cylinder engine are investigated analytically.